PRIOR ART STATEMENT
The inventor knows of the following U.S. patents related to this invention and discovered during a preliminary patent search: U.S. Pat. Nos. 4,215,897 4,189,178 4,341,416 4,162,100. The inventor is not withholding any other known prior art which he considers anticipates this invention.
This invention relates to a new covering system for trucks and in particular to a covering system which allows a tarpaulin cover to be mechanically drawn or withdrawn from the top portion of the truck bed.
The use of truck covering has long bee recognized as a necessity for trucks. It is particularly true in dump trucks carrying loose sand, gravel, stones and the like. In particular, trucks carrying asphalt are frequently required by law to be appropriately covered.
This invention is a unique device for mechanically covering and uncovering the bed of a truck. In its covered phase the device will completely enclose and cover the truck bed area allowing no opening. The advantages and features of this device are that it reduces driver fatigue in covering the truck bed and also reduces risk of injury considerably.
The driver can place the tarpaulin over the load in the truck bed by turning a hand crank placed near the cab door. Turning the crank in one direction moves the tarpaulin over the load. Turning the crank in the reverse direction removes the tarpaulin from over the load. The device will fit most dump trucks on the market today. One advantage is that it is not over-width (96 inches).
The system works similarly to a curtain rod. It has a support member on each side, which is also used as a guide rail for tarpaulin supports to slide on. It has pulley on each end of the guide rail the cable is attached around the two pulleys--one assembly on each side of the truck bed. The cable runs through a number of wooden slats ( the actual number depends on the length of the truck bed). The slats have holes drilled near the ends to allow the cable to slide freely through them. The rear most slat is attached to the cable so when the cable is moved in either direction the slat moves with it. With the attached slat to the rear of the truck, the remainder of the slats are spaced about two feet apart--between the front pulleys and the rear most slat.
The tarpaulin being presized for the truck, is fastened at the front end near or in line with the front cable pulleys. It is spread over the slats and fastened to the prespaced slats. The slats have a small metal device attached to the end allowing the tarpaulin to come down over the sides of the truck bed 4 to 6 inches to completely cover the truck bed. With tarpaulin in place and fastened, it simply covers or uncovers the load by rotating the cable.
The cable assembly is rotated by a simple chain drive assembly. The two front cable pulleys are attached rigidly to a cross shaft. On this shaft is attached a chain sprocket. Near the left hand door of the truck cab is attached another sprocket of the same size as the one on the tarpaulin cross shaft. The sprocket is attached under the cab shield by the front of the truck bed by means of a pair of bearings--short shaft--and a fabricated bracket. The two sprockets are connected with a suitable roller chain.
A hand crank handle is fashioned to fit over the drive sprocket shaft. The crank handle is designed so it is removable when not in use, thus not sticking out beyond legal width of truck bed. The crank shaft has a simple locking device to prevent tarpaulin moving from forward or rear position until unlocking of shaft allowing it to turn. It should be noted that the tarpaulin extends over the sides of the truck to completely enclose the covered contents.
An important feature of this invention is that the tarpaulin covers and seals or encloses the top portion of the side walls, front and rear walls of the truck bed when in the extended covering position This is done by securing the sides of the tarpaulin to L-shaped tarpaulin supports attached to the end of each slat. These tarpaulin supports extend downwardly over the sides of the truck bed and hold the tarpaulin over the truck bed.
It is an object of this invention therefore to construct a device which will cover the top, sides and ends of a truck bed without the use of additional fasteners or straps.
It is still another object of this device to provide a truck covering mechanism which will extend over the sides, front and rear of the truck bed to completely cover its contents.
It is yet another object of this invention to provide a cable tension adjusting mechanism which will easily and simply vary the tension of the operating cables of the device.
It is another object of this invention to provide a simple to use and easy cover for a truck that may be mechanically drawn over a truck bed or removed from the truck bed in seconds.
It is another object of this device to reduce driver fatigue and injuries by allowing the manipulation of the device from near the truck cab.
It is yet another object of this invention to provide a truck covering device, installable on most trucks, in which all lateral operating mechanisms are completely covered by the truck frame and body.
It is still another object of this invention to provide a truck covering device which will not extend beyond in width the legal width limit of a truck.